/**
 * ****************************************************************************
 * Spine Runtimes Software License Version 2
 *
 * Copyright (c) 2013, Esoteric Software All rights reserved.
 *
 * You are granted a perpetual, non-exclusive, non-sublicensable and
 * non-transferable license to install, execute and perform the Spine Runtimes
 * Software (the "Software") solely for internal use. Without the written
 * permission of Esoteric Software, you may not (a) modify, translate, adapt or
 * otherwise create derivative works, improvements of the Software or develop
 * new applications using the Software or (b) remove, delete, alter or obscure
 * any trademarks or any copyright, trademark, patent or other intellectual
 * property or proprietary rights notices on or in the Software, including any
 * copy thereof. Redistributions in binary or source form must include this
 * license and terms. THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTARE BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ***************************************************************************
 */
package sg.atom2d.game2d.graphics.anim.spine.skeleton;

import sg.atom2d.game2d.graphics.anim.spine.attachments.Attachment;
import sg.atom2d.game2d.graphics.anim.spine.attachments.MeshAttachment;
import sg.atom2d.game2d.graphics.anim.spine.attachments.RegionAttachment;
import sg.atom2d.game2d.graphics.anim.spine.attachments.SkeletonAttachment;

import com.badlogic.gdx.graphics.GL11;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.g2d.PolygonSpriteBatch;
import sg.atom.utils.collection.Array;
import sg.atom2d.game2d.graphics.anim.spine.Slot;

public class SkeletonRenderer {

    static private final short[] quadTriangle = {0, 1, 2, 2, 3, 0};
    private boolean premultipliedAlpha;

    public void draw(PolygonSpriteBatch batch, Skeleton skeleton) {
        boolean premultipliedAlpha = this.premultipliedAlpha;
        int srcFunc = premultipliedAlpha ? GL11.GL_ONE : GL11.GL_SRC_ALPHA;
        batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);

        boolean additive = false;

        float[] vertices;
        short[] triangles;
        Texture texture;
        Array<Slot> drawOrder = skeleton.drawOrder;
        for (int i = 0, n = drawOrder.size; i < n; i++) {
            Slot slot = drawOrder.get(i);
            Attachment attachment = slot.attachment;
            if (attachment instanceof RegionAttachment) {
                RegionAttachment region = (RegionAttachment) attachment;
                region.updateWorldVertices(slot, premultipliedAlpha);
                vertices = region.getWorldVertices();
                triangles = quadTriangle;
                texture = region.getRegion().getTexture();

                if (slot.data.getAdditiveBlending() != additive) {
                    additive = !additive;
                    if (additive) {
                        batch.setBlendFunction(srcFunc, GL11.GL_ONE);
                    } else {
                        batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);
                    }
                }

                batch.draw(texture, vertices, 0, vertices.length, triangles, 0, triangles.length);

            } else if (attachment instanceof MeshAttachment) {
                MeshAttachment mesh = (MeshAttachment) attachment;
                mesh.updateWorldVertices(slot, true);
                vertices = mesh.getWorldVertices();
                triangles = mesh.getTriangles();
                texture = mesh.getRegion().getTexture();
                batch.draw(texture, vertices, 0, vertices.length, triangles, 0, triangles.length);

            } else if (attachment instanceof SkeletonAttachment) {
                Skeleton attachmentSkeleton = ((SkeletonAttachment) attachment).getSkeleton();
                if (attachmentSkeleton == null) {
                    continue;
                }
                Bone bone = slot.getBone();
                Bone rootBone = attachmentSkeleton.getRootBone();
                float oldScaleX = rootBone.getScaleX();
                float oldScaleY = rootBone.getScaleY();
                float oldRotation = rootBone.getRotation();
                attachmentSkeleton.setX(bone.getWorldX());
                attachmentSkeleton.setY(bone.getWorldY());
                rootBone.setScaleX(1 + bone.getWorldScaleX() - oldScaleX);
                rootBone.setScaleY(1 + bone.getWorldScaleY() - oldScaleY);
                rootBone.setRotation(oldRotation + bone.getWorldRotation());
                attachmentSkeleton.updateWorldTransform();

                draw(batch, attachmentSkeleton);

                attachmentSkeleton.setX(0);
                attachmentSkeleton.setY(0);
                rootBone.setScaleX(oldScaleX);
                rootBone.setScaleY(oldScaleY);
                rootBone.setRotation(oldRotation);
            }
        }
    }

    public void draw(Batch batch, Skeleton skeleton) {
        boolean premultipliedAlpha = this.premultipliedAlpha;
        int srcFunc = premultipliedAlpha ? GL11.GL_ONE : GL11.GL_SRC_ALPHA;
        batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);

        boolean additive = false;

        Array<Slot> drawOrder = skeleton.drawOrder;
        for (int i = 0, n = drawOrder.size; i < n; i++) {
            Slot slot = drawOrder.get(i);
            Attachment attachment = slot.attachment;
            if (attachment instanceof RegionAttachment) {
                RegionAttachment regionAttachment = (RegionAttachment) attachment;
                regionAttachment.updateWorldVertices(slot, premultipliedAlpha);
                float[] vertices = regionAttachment.getWorldVertices();
                if (slot.data.getAdditiveBlending() != additive) {
                    additive = !additive;
                    if (additive) {
                        batch.setBlendFunction(srcFunc, GL11.GL_ONE);
                    } else {
                        batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);
                    }
                }
                batch.draw(regionAttachment.getRegion().getTexture(), vertices, 0, 20);
            } else if (attachment instanceof SkeletonAttachment) {
                Skeleton attachmentSkeleton = ((SkeletonAttachment) attachment).getSkeleton();
                if (attachmentSkeleton == null) {
                    continue;
                }
                Bone bone = slot.getBone();
                Bone rootBone = attachmentSkeleton.getRootBone();
                float oldScaleX = rootBone.getScaleX();
                float oldScaleY = rootBone.getScaleY();
                float oldRotation = rootBone.getRotation();
                attachmentSkeleton.setX(bone.getWorldX());
                attachmentSkeleton.setY(bone.getWorldY());
                rootBone.setScaleX(1 + bone.getWorldScaleX() - oldScaleX);
                rootBone.setScaleY(1 + bone.getWorldScaleY() - oldScaleY);
                rootBone.setRotation(oldRotation + bone.getWorldRotation());
                attachmentSkeleton.updateWorldTransform();

                draw(batch, attachmentSkeleton);

                attachmentSkeleton.setX(0);
                attachmentSkeleton.setY(0);
                rootBone.setScaleX(oldScaleX);
                rootBone.setScaleY(oldScaleY);
                rootBone.setRotation(oldRotation);
            }
        }
    }

    public void setPremultipliedAlpha(boolean premultipliedAlpha) {
        this.premultipliedAlpha = premultipliedAlpha;
    }
}
